If the game freezes, just click inside it (games can get unresponsive if you click elsewhere on the page).
Fight your way through hordes of zombies in order to find a way out. Upgrade your weapons to take them out, but watch out, when you run out of ammo you are going to need to run back to the saloon. Why don't you take a rest and have a go at the mini-game and earn a few more coins to spend in store. Good luck.